Echinacea Root Extracts for the Prevention of Upper Respiratory Tract Infections

Author(s): Melchart, D., Walther, E. , Linde, K. , Brandmaier, R. , Lersch, C.

Journal/Book: Arch Fam Med. 1998; 7: 541-545.

Keyword(s): phyto. cr. prev. urt-inf. echinacea.